261396 has 36 divisors (see below), whose sum is σ = 678132. Its totient is φ = 84864.

The previous prime is 261389. The next prime is 261407. The reversal of 261396 is 693162.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 171396 + 90000 = 414^2 + 300^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261396.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1840 + ... + 1976.

It is an arithmetic number, because the mean of its divisors is an integer number (18837).

2²⁶¹³⁹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (339066).

261396 is an abundant number, since it is smaller than the sum of its proper divisors (416736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261396 is a wasteful number, since it uses less digits than its factorization.

261396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 195 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 261396 is about 511.2690094265. The cubic root of 261396 is about 63.9390696146.

The spelling of 261396 in words is "two hundred sixty-one thousand, three hundred ninety-six".